To form a color photographic image, photographic couplers for three colors; that is, for yellow, magenta, and cyan, are contained in photosensitive layers, and after exposure to light they are processed with a color developer containing a color-developing agent. In this step, the couplers react with the oxidized product of an aromatic primary amine to form color-formed dyes.
Generally, the standard processing steps of silver halide color photographic materials comprise a color-development step of forming a color image, a desilvering step of removing developed silver and undeveloped silver, and a washing step and/or an image stabilizing step.
Although efforts have hitherto been made to shorten the processing time, recently the need for shortening the processing time has heightened because of a demand for shortening the time of the delivery of the finished product, a demand for reduction of labor in the photofinisher, a demand for minimizing the processing system for a small-scale photofinisher (a so-called compact lab), and a demand for simplification of the operation.
Shortening the time of the color-development step can be attained by suitably combining the use of a coupler whose coupling speed is increased as much as possible, the use of a silver halide emulsion whose developing speed is high, the use of a color developer whose developing speed is high, and by increasing the temperature of the color developer.
The shortening of the desilvering step can be attained by lowering the pH of the bleaching solution and the bleach-fix solution. That the bleach-fix may be quickened by lowering the pH of the bleach-fix solution is described in The Theory of the Photographic Process, Chapter 15, E. Bleach-Fix System.
However, lowering the pH of the bleach-fix solution increases the bleaching speed, but the dye formed from a cyan coupler is decolored by leuco dye formation and it is not restored until completion of the processing (hereinafter this phenomenon is referred to as insufficiency of color formation), causing a drop in the density and leading to the problem of the color being gradually restored after processing and the color balance being lost, which lowers the image quality.
As a means of improving this, there is an improved method wherein, after color development, washing is carried out, and after removing the developing agent, a bleach-fix process is carried out. But the method is accompanied by defects in that the number of steps increases and the total period of processing becomes longer.
As other improving means, addition of a water-soluble ionic compound containing a polyvalent element to a bleach-fix bath is suggested, for example, in U.S. Pat. No. 3,773,510, but that technique has defects in that the load on pollution increases and the intended purpose is not yet satisfactory.
Conventionally, for the purpose of adjusting the gradation, preventing fogging, and preventing fading of mainly magenta dyes, the use of hydroquinones and quinones is described in JP-A ("JP-A" means unexamined published Japanese patent application) Nos. 161238/1980, 60647/1985, and 32034/1978, West German Patent Application Laid-Open Nos. 2,149,789 and 3,320,483Al, JP-A Nos. 24141/1983 and 2128/1971, JP-B ("JP-B" means examined Japanese patent publication) Nos. 4934/1968, 21249/1975, and 3171/1985, JP-A Nos. 106329/1974 and 129535/1974, British Patent No. 1,465,081, JP-A Nos. 129536/1974,134327/1974, 110337/1975, 156438/1975, 6024/1976, 9828/1976, 14023/1976, 65432/1977, 128130/1977, 146234/1977, 146235/1977, 9528/1978, 55121/1978, 139533/1978, 24019/1979, 25823/1979, 29637/1979, 70036/1979, 97021/1979, 133181/1979, 95948/1980, 5543/1981, 83742/1981, 85748/1981, 87040/1981, 153342/1981, 112749/1982, 176038/1982, 136030/1983, 72443/1984, 75249/1984, 83162/1984, 101650/1984, 180557/1984, 60647/1985, 189342/1984, 191031/1984, 55339/1985, and 263149/1985, Research Disclosure (R.D.) 22827 (1983), and U.S. Pat. Nos. 2,384,658, 2,403,721, 2,728,659, 2,735,765, 3,700,453, 2,675,314, 2,732,300, and 2,360,290 and the prevention of fogging particularly by using a hydroquinone substituted by an electron attractive group in an intermediate layer is described in JP-B No. 35012/1984, and JP-A Nos. 109344/1981 and 22237/1982. But they do not disclose anything as to insufficiency of color formation.
It is known that the addition of a hydroquinone is liable to bring about the insufficiency of color formation when hydroquinone is used in a bleach-fix bath whose pH is high and into which a color developer has interfused; on the contrary JP-A No. 60647/1985 suggests reducing the amount of hydroquinones to be used.
Further, JP-A No. 316857/1988 suggests the use of alkyl-group-substituted hydroquinones or quinones to improve the insufficiency of color formation in a bleach-fix bath whose pH is low, and although the effect is indeed recognized, further improvement is desired. Also, in this method a new problem has been found. When the processed photographic material is stored under very intense light, the cyan image is deteriorated.
Further, JP-A No. 316857/1988 suggests the use of halogen-substituted hydroquinones or quinones to improve the insufficiency of color formation in a bleach-fix bath whose pH is low and to improve on the deterioration of the cyan color image. But a new problem has been found that when the halogen-substituted hydroquinones or quinones are used in a red-sensitive layer, the change of sensitivity and gradation (hereinafter referred to as latent-image preservability) during the period from exposure to light to the development processing is conspicuous.
JP-A No. 189649/1989 describes that a red-sensitive sensitizing dye having a reduction potential of -1.25 V (vs SEC) or more negative can improve the preservability of a raw stock (unexposed and unprocessed photographic material) with time, but it describes neither latent-image preservability nor the insufficiency of color formation.